/*2012-2-19
 Des 加密和解密算法
 有两份代码，都能正常工作；
 第一份被注释的是只有对应8字节操作的
 第二份可以文件对文件操作
 */

/*#include "memory.h"
 #include "stdio.h"
 
 enum    {ENCRYPT,DECRYPT};// ENCRYPT:加密,DECRYPT:解密
 void Des_Run(char Out[8], char In[8], bool Type=ENCRYPT);
 void Des_SetKey(const char Key[8]);// 设置密钥
 static void F_func(bool In[32], const bool Ki[48]);// f 函数
 static void S_func(bool Out[32], const bool In[48]);// S 盒代替
 static void Transform(bool *Out, bool *In, const char *Table, int len);// 变换
 static void Xor(bool *InA, const bool *InB, int len);// 异或
 static void RotateL(bool *In, int len, int loop);// 循环左移
 static void ByteToBit(bool *Out, const char *In, int bits);// 字节组转换成位组
 static void BitToByte(char *Out, const bool *In, int bits);// 位组转换成字节组
 //置换IP表
 const static char IP_Table[64] = {
 58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,
 62,54,46,38,30,22,14,6,64,56,48,40,32,24,16,8,
 57,49,41,33,25,17,9,1,59,51,43,35,27,19,11,3,
 61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7
 };
 //逆置换IP-1表
 const static char IPR_Table[64] = {
 40,8,48,16,56,24,64,32,39,7,47,15,55,23,63,31,
 38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,
 36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,
 34,2,42,10,50,18,58,26,33,1,41,9,49,17,57,25
 };
 //E位选择表(扩展置换表)
 static const char E_Table[48] = {
 32,1,2,3,4,5,4,5,6,7,8,9,
 8,9,10,11,12,13,12,13,14,15,16,17,
 16,17,18,19,20,21,20,21,22,23,24,25,
 24,25,26,27,28,29,28,29,30,31,32,1
 };
 //P换位表(单纯换位表)
 const static char P_Table[32] = {
 16,7,20,21,29,12,28,17,1,15,23,26,5,18,31,10,
 2,8,24,14,32,27,3,9,19,13,30,6,22,11,4,25
 };
 //PC1选位表(密钥生成置换表1)
 const static char PC1_Table[56] = {
 57,49,41,33,25,17,9,1,58,50,42,34,26,18,
 10,2,59,51,43,35,27,19,11,3,60,52,44,36,
 63,55,47,39,31,23,15,7,62,54,46,38,30,22,
 14,6,61,53,45,37,29,21,13,5,28,20,12,4
 };
 //PC2选位表(密钥生成置换表2)
 const static char PC2_Table[48] = {
 14,17,11,24,1,5,3,28,15,6,21,10,
 23,19,12,4,26,8,16,7,27,20,13,2,
 41,52,31,37,47,55,30,40,51,45,33,48,
 44,49,39,56,34,53,46,42,50,36,29,32
 };
 //左移位数表
 const static char LOOP_Table[16] = {
 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
 };
 // S盒
 const static char S_Box[8][4][16] = {
 // S1
 14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7,
 0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8,
 4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0,
 15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13,
 //S2
 15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10,
 3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5,
 0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15,
 13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9,
 //S3
 10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,
 13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,
 13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,
 1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12,
 //S4
 7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,
 13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,
 10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,
 3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14,
 //S5
 2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,
 14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6,
 4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14,
 11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3,
 //S6
 12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11,
 10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8,
 9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6,
 4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13,
 //S7
 4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,
 13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6,
 1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,
 6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12,
 //S8
 13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7,
 1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2,
 7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8,
 2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11
 };
 
 static bool SubKey[16][48];// 16圈子密钥
 
 void Des_Run(char Out[8], char In[8], bool Type)
 {
 static bool M[64], Tmp[32], *Li = &M[0], *Ri = &M[32];
 ByteToBit(M, In, 64);// 字节组转换成位组
 Transform(M, M, IP_Table, 64);// 变换
 if( Type == ENCRYPT ){
 for(int i=0; i<16; i++) {
 memcpy(Tmp, Ri, 32);
 F_func(Ri, SubKey[i]);
 Xor(Ri, Li, 32);// 异或
 memcpy(Li, Tmp, 32);
 }
 }else{
 for(int i=15; i>=0; i--) {
 memcpy(Tmp, Li, 32);
 F_func(Li, SubKey[i]);
 Xor(Li, Ri, 32);// 异或
 memcpy(Ri, Tmp, 32);
 }
 }
 Transform(M, M, IPR_Table, 64);// 变换
 BitToByte(Out, M, 64);
 }
 
 
 void Des_SetKey(const char Key[8])
 {
 static bool K[64], *KL = &K[0], *KR = &K[28];
 ByteToBit(K, Key, 64);// 字节组转换成位组
 Transform(K, K, PC1_Table, 56);// 变换
 for(int i=0; i<16; i++)
 {
 RotateL(KL, 28, LOOP_Table[i]);// 循环左移
 RotateL(KR, 28, LOOP_Table[i]);// 循环左移
 Transform(SubKey[i], K, PC2_Table, 48);// 变换
 }
 }
 
 
 
 void F_func(bool In[32], const bool Ki[48])// f 函数
 {
 static bool MR[48];
 Transform(MR, In, E_Table, 48);// 变换
 Xor(MR, Ki, 48);// 异或
 S_func(In, MR);// S 盒代替
 Transform(In, In, P_Table, 32);// 变换
 }
 
 void S_func(bool Out[32], const bool In[48])// S 盒代替,输入6位的数，输出4位的数，将第一六位对应的十进制数作为行，第二三四五为的对应十进制数作为列
 {
 for(char i=0,j,k; i<8; i++,In+=6,Out+=4)
 {
 j = (In[0]<<1) + In[5];
 k = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4];
 ByteToBit(Out, &S_Box[i][j][k], 4);
 }
 }
 
 void Transform(bool *Out, bool *In, const char *Table, int len)//变换
 {
 static bool Tmp[256];
 for(int i = 0; i < len; i++)
 {
 Tmp[i] = In[ Table[i] - 1 ];
 }
 memcpy(Out, Tmp, len);
 }
 
 
 
 void Xor(bool *InA, const bool *InB, int len)//异或
 {
 for(int i = 0; i < len; i++)
 {
 InA[i] ^= InB[i];
 }
 }
 
 void RotateL(bool *In, int len, int loop)//循环左移
 {
 static bool Tmp[256];
 memcpy(Tmp, In, loop);
 memcpy(In, In+loop, len-loop);
 memcpy(In+len-loop, Tmp, loop);
 }
 
 void ByteToBit(bool *Out, const char *In, int bits)//字节组转换成位组
 {
 for(int i = 0; i < bits; i++)
 {
 Out[i] = (In[i/8] >> (i%8)) & 1;
 }
 }
 
 void BitToByte(char *Out, const bool *In, int bits)
 {
 memset(Out, 0, (bits+7)/8);
 for(int i = 0; i < bits; i++)
 {
 Out[i/8] |= In[i] << (i%8);
 }
 }
 */
/*
 int main(int argc, char *argv[])
 {
 char key[8] = {1, 9, 8, 0, 9, 1, 7, 2}, str[] = "Hello";
 puts("Before encrypting");
 puts(str);
 Des_SetKey(key);
 Des_Run(str, str, ENCRYPT);
 puts("After decrypting");
 printf("%x",str);
 puts(str);
 puts("After decrypting");
 Des_Run(str, str, DECRYPT);
 puts(str);
 
 return 0;
 
 }
 */

#include "stdio.h"
#include "memory.h"
#include "time.h"

#include "stdlib.h"


#define PLAIN_FILE_OPEN_ERROR -1

#define KEY_FILE_OPEN_ERROR -2

#define CIPHER_FILE_OPEN_ERROR -3

#define OK 1;

typedef char ElemType;

/* 初始置换表IP */

int IP_Table[64] = { 57,49,41,33,25,17,9,1,
    
    59,51,43,35,27,19,11,3,
    
    61,53,45,37,29,21,13,5,
    
    63,55,47,39,31,23,15,7,
    
    56,48,40,32,24,16,8,0,
    
    58,50,42,34,26,18,10,2,
    
    60,52,44,36,28,20,12,4,
    
    62,54,46,38,30,22,14,6};

/* 逆初始置换表IP^-1 */

int IP_1_Table[64] = {39,7,47,15,55,23,63,31,
    
    38,6,46,14,54,22,62,30,
    
    37,5,45,13,53,21,61,29,
    
    36,4,44,12,52,20,60,28,
    
    35,3,43,11,51,19,59,27,
    
    34,2,42,10,50,18,58,26,
    
    33,1,41,9,49,17,57,25,
    
    32,0,40,8,48,16,56,24};


/* 扩充置换表E */

int E_Table[48] = {31, 0, 1, 2, 3, 4,
    
    3, 4, 5, 6, 7, 8,
    
    7, 8,9,10,11,12,
    
    11,12,13,14,15,16,
    
    15,16,17,18,19,20,
    
    19,20,21,22,23,24,
    
    23,24,25,26,27,28,
    
    27,28,29,30,31, 0};


/* 置换函数P */

int P_Table[32] = {15,6,19,20,28,11,27,16,
    
    0,14,22,25,4,17,30,9,
    
    1,7,23,13,31,26,2,8,
    
    18,12,29,5,21,10,3,24};


/* S盒 */

int S[8][4][16] =/* S1 */

{{{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},
    
    {0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},
    
    {4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},
    
    {15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}},
    
    /* S2 */
    
    {{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},
        
        {3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},
        
        {0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},
        
        {13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}},
    
    /* S3 */
    
    {{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},
        
        {13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},
        
        {13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},
        
        {1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}},
    
    /* S4 */
    
    {{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},
        
        {13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},
        
        {10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},
        
        {3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}},
    
    /* S5 */
    
    {{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},
        
        {14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},
        
        {4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},
        
        {11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}},
    
    /* S6 */
    
    {{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},
        
        {10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},
        
        {9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},
        
        {4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}},
    
    /* S7 */
    
    {{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},
        
        {13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},
        
        {1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},
        
        {6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}},
    
    /* S8 */
    
    {{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},
        
        {1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},
        
        {7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},
        
        {2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}}};

/* 置换选择1 */

int PC_1[56] = {56,48,40,32,24,16,8,
    
    0,57,49,41,33,25,17,
    
    9,1,58,50,42,34,26,
    
    18,10,2,59,51,43,35,
    
    62,54,46,38,30,22,14,
    
    6,61,53,45,37,29,21,
    
    13,5,60,52,44,36,28,
    
    20,12,4,27,19,11,3};


/* 置换选择2 */

int PC_2[48] = {13,16,10,23,0,4,2,27,
    
    14,5,20,9,22,18,11,3,
    
    25,7,15,6,26,19,12,1,
    
    40,51,30,36,46,54,29,39,
    
    50,44,32,46,43,48,38,55,
    
    33,52,45,41,49,35,28,31};


/* 对左移次数的规定 */

int MOVE_TIMES[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};

int ByteToBit(ElemType ch,ElemType bit[8]);

int BitToByte(ElemType bit[8],ElemType *ch);

int Char8ToBit64(ElemType ch[8],ElemType bit[64]);

int Bit64ToChar8(ElemType bit[64],ElemType ch[8]);

int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]);

int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]);

int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]);

int DES_ROL(ElemType data[56], int time);

int DES_IP_Transform(ElemType data[64]);

int DES_IP_1_Transform(ElemType data[64]);

int DES_E_Transform(ElemType data[48]);

int DES_P_Transform(ElemType data[32]);

int DES_SBOX(ElemType data[48]);

int DES_XOR(ElemType R[48], ElemType L[48],int count);

int DES_Swap(ElemType left[32],ElemType right[32]);

int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]);

int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48], ElemType plainBlock[8]);

int DES_Encrypt(char *plainFile, char *keyStr,char *cipherFile);

int DES_Decrypt(char *cipherFile, char *keyStr,char *plainFile);

/* 字节转换成二进制 */

int ByteToBit(ElemType ch, ElemType bit[8]){
    
	int cnt;
    
	for(cnt = 0;cnt < 8; cnt++){
        
		*(bit+cnt) = (ch>>cnt)&1;
        
	}
    
	return 0;
    
}


/* 二进制转换成字节 */

int BitToByte(ElemType bit[8],ElemType *ch){
    
	int cnt;
    
	for(cnt = 0;cnt < 8; cnt++){
        
		*ch |= *(bit + cnt)<<cnt;
        
	}
    
	return 0;
    
}


/* 将长度为8的字符串转为二进制位串 */

int Char8ToBit64(ElemType ch[8],ElemType bit[64]){
    
	int cnt;
    
	for(cnt = 0; cnt < 8; cnt++){
        
		ByteToBit(*(ch+cnt),bit+(cnt<<3));
        
	}
    
	return 0;
    
}


/* 将二进制位串转为长度为8的字符串 */

int Bit64ToChar8(ElemType bit[64],ElemType ch[8]){
    
	int cnt;
    
	memset(ch,0,8);
    
	for(cnt = 0; cnt < 8; cnt++){
        
		BitToByte(bit+(cnt<<3),ch+cnt);
        
	}
    
	return 0;
    
}


/* 生成子密钥 */

int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]){
    
	ElemType temp[56];
    
	int cnt;
    
	DES_PC1_Transform(key,temp);/* PC1置换 */
    
	for(cnt = 0; cnt < 16; cnt++){/* 16轮跌代，产生16个子密钥 */
        
		DES_ROL(temp,MOVE_TIMES[cnt]);/* 循环左移 */
        
		DES_PC2_Transform(temp,subKeys[cnt]);/* PC2置换，产生子密钥 */
        
	}
    
	return 0;
    
}


/* 密钥置换1 */

int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]){
    
	int cnt;
    
	for(cnt = 0; cnt < 56; cnt++){
        
		tempbts[cnt] = key[PC_1[cnt]];
        
	}
    
	return 0;
    
}


/* 密钥置换2 */

int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]){
    
	int cnt;
    
	for(cnt = 0; cnt < 48; cnt++){
        
		tempbts[cnt] = key[PC_2[cnt]];
        
	}
    
	return 0;
    
}


/* 循环左移 */

int DES_ROL(ElemType data[56], int time){
    
	ElemType temp[56];
    
    
	/* 保存将要循环移动到右边的位 */
    
	memcpy(temp,data,time);
    
	memcpy(temp+time,data+28,time);
    
    
    
	/* 前28位移动 */
    
	memcpy(data,data+time,28-time);
    
	memcpy(data+28-time,temp,time);
    
    
	/* 后28位移动 */
    
	memcpy(data+28,data+28+time,28-time);
    
	memcpy(data+56-time,temp+time,time);
    
    
	return 0;
    
}


/* IP置换 */

int DES_IP_Transform(ElemType data[64]){
    
	int cnt;
    
	ElemType temp[64];
    
	for(cnt = 0; cnt < 64; cnt++){
        
		temp[cnt] = data[IP_Table[cnt]];
        
	}
    
	memcpy(data,temp,64);
    
	return 0;
    
}


/* IP逆置换 */

int DES_IP_1_Transform(ElemType data[64]){
    
	int cnt;
    
	ElemType temp[64];
    
	for(cnt = 0; cnt < 64; cnt++){
        
		temp[cnt] = data[IP_1_Table[cnt]];
        
	}
    
	memcpy(data,temp,64);
    
	return 0;
    
}


/* 扩展置换 */

int DES_E_Transform(ElemType data[48]){
    
	int cnt;
    
	ElemType temp[48];
    
	for(cnt = 0; cnt < 48; cnt++){
        
		temp[cnt] = data[E_Table[cnt]];
        
	}
    
	memcpy(data,temp,48);
    
	return 0;
    
}


/* P置换 */

int DES_P_Transform(ElemType data[32]){
    
	int cnt;
    
	ElemType temp[32];
    
	for(cnt = 0; cnt < 32; cnt++){
        
		temp[cnt] = data[P_Table[cnt]];
        
	}
    
	memcpy(data,temp,32);
    
	return 0;
    
}


/* 异或 */

int DES_XOR(ElemType R[48], ElemType L[48] ,int count){
    
	int cnt;
    
	for(cnt = 0; cnt < count; cnt++){
        
		R[cnt] ^= L[cnt];
        
	}
    
	return 0;
    
}


/* S盒置换 */

int DES_SBOX(ElemType data[48]){
    
	int cnt;
    
	int line,row,output;
    
	int cur1,cur2;
    
	for(cnt = 0; cnt < 8; cnt++){
        
		cur1 = cnt*6;
        
		cur2 = cnt<<2;
        
        
        
		/* 计算在S盒中的行与列 */
        
		line = (data[cur1]<<1) + data[cur1+5];
        
		row = (data[cur1+1]<<3) + (data[cur1+2]<<2)
        
        + (data[cur1+3]<<1) + data[cur1+4];
        
		output = S[cnt][line][row];
        
        
		/* 化为2进制 */
        
		data[cur2] = (output&0X08)>>3;
        
		data[cur2+1] = (output&0X04)>>2;
        
		data[cur2+2] = (output&0X02)>>1;
        
		data[cur2+3] = output&0x01;
        
	}
    
	return 0;
    
}


/* 交换 */

int DES_Swap(ElemType left[32], ElemType right[32]){
    
	ElemType temp[32];
    
	memcpy(temp,left,32);
    
	memcpy(left,right,32);
    
	memcpy(right,temp,32);
    
	return 0;
    
}


/* 加密单个分组 */

int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]){
    
	ElemType plainBits[64];
    
	ElemType copyRight[48];
    
	int cnt;
    
    
	Char8ToBit64(plainBlock,plainBits);
    
	/* 初始置换（IP置换） */
    
	DES_IP_Transform(plainBits);
    
    
	/* 16轮迭代 */
    
	for(cnt = 0; cnt < 16; cnt++){
        
		memcpy(copyRight,plainBits+32,32);
        
		/* 将右半部分进行扩展置换，从32位扩展到48位 */
        
		DES_E_Transform(copyRight);
        
		/* 将右半部分与子密钥进行异或操作 */
        
		DES_XOR(copyRight,subKeys[cnt],48);
        
		/* 异或结果进入S盒，输出32位结果 */
        
		DES_SBOX(copyRight);
        
		/* P置换 */
        
		DES_P_Transform(copyRight);
        
		/* 将明文左半部分与右半部分进行异或 */
        
		DES_XOR(plainBits,copyRight,32);
        
		if(cnt != 15){
            
			/* 最终完成左右部的交换 */
            
			DES_Swap(plainBits,plainBits+32);
            
		}
        
	}
    
	/* 逆初始置换（IP^1置换） */
    
	DES_IP_1_Transform(plainBits);
    
	Bit64ToChar8(plainBits,cipherBlock);
    
	return 0;
    
}


/* 解密单个分组 */

int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48],ElemType plainBlock[8]){
    
	ElemType cipherBits[64];
    
	ElemType copyRight[48];
    
	int cnt;
    
    
	Char8ToBit64(cipherBlock,cipherBits);
    
	/* 初始置换（IP置换） */
    
	DES_IP_Transform(cipherBits);
    
    
    
	/* 16轮迭代 */
    
	for(cnt = 15; cnt >= 0; cnt--){
        
		memcpy(copyRight,cipherBits+32,32);
        
		/* 将右半部分进行扩展置换，从32位扩展到48位 */
        
		DES_E_Transform(copyRight);
        
		/* 将右半部分与子密钥进行异或操作 */
        
		DES_XOR(copyRight,subKeys[cnt],48);
        
		/* 异或结果进入S盒，输出32位结果 */
        
		DES_SBOX(copyRight);
        
		/* P置换 */
        
		DES_P_Transform(copyRight);
        
		/* 将明文左半部分与右半部分进行异或 */
        
		DES_XOR(cipherBits,copyRight,32);
        
		if(cnt != 0){
            
			/* 最终完成左右部的交换 */
            
			DES_Swap(cipherBits,cipherBits+32);
            
		}
        
	}
    
	/* 逆初始置换（IP^1置换） */
    
	DES_IP_1_Transform(cipherBits);
    
	Bit64ToChar8(cipherBits,plainBlock);
    
	return 0;
    
}


/* 加密文件 */

int DES_Encrypt(char *plainFile, char *keyStr,char *cipherFile){
    
	FILE *plain,*cipher;
    
	int count;
    
	ElemType plainBlock[8],cipherBlock[8],keyBlock[8];
    
	ElemType bKey[64];
    
	ElemType subKeys[16][48];
    
	if((plain = fopen(plainFile,"rb")) == NULL){
        
		return PLAIN_FILE_OPEN_ERROR;
        
	}
    
	if((cipher = fopen(cipherFile,"wb")) == NULL){
        
		return CIPHER_FILE_OPEN_ERROR;
        
	}
    
	/* 设置密钥 */
    
	memcpy(keyBlock,keyStr,8);
    
	/* 将密钥转换为二进制流 */
    
	Char8ToBit64(keyBlock,bKey);
    
	/* 生成子密钥 */
    
	DES_MakeSubKeys(bKey,subKeys);
    
    
    
	while(!feof(plain)){
        
		/* 每次读8个字节，并返回成功读取的字节数 */
        
		if((count = fread(plainBlock,sizeof(char),8,plain)) == 8){
            
			DES_EncryptBlock(plainBlock,subKeys,cipherBlock);
            
			fwrite(cipherBlock,sizeof(char),8,cipher);   
            
		}
        
	}
    
	if(count){
        
		/* 填充 */
        
		memset(plainBlock + count,'\0',7 - count);
        
		/* 最后一个字符保存包括最后一个字符在内的所填充的字符数量 */
        
		plainBlock[7] = 8 - count;
        
		DES_EncryptBlock(plainBlock,subKeys,cipherBlock);
        
		fwrite(cipherBlock,sizeof(char),8,cipher);
        
	}
    
	fclose(plain);
    
	fclose(cipher);
    
	return OK;
    
}


/* 解密文件 */

int DES_Decrypt(char *cipherFile, char *keyStr,char *plainFile){
    
	FILE *plain, *cipher;
    
	int count,times = 0;
    
	long fileLen;
    
	ElemType plainBlock[8],cipherBlock[8],keyBlock[8];
    
	ElemType bKey[64];
    
	ElemType subKeys[16][48];
    
	if((cipher = fopen(cipherFile,"rb")) == NULL){
        
		return CIPHER_FILE_OPEN_ERROR;
        
	}
    
	if((plain = fopen(plainFile,"wb")) == NULL){
        
		return PLAIN_FILE_OPEN_ERROR;
        
	}
    
    
	/* 设置密钥 */
    
	memcpy(keyBlock,keyStr,8);
    
	/* 将密钥转换为二进制流 */
    
	Char8ToBit64(keyBlock,bKey);
    
	/* 生成子密钥 */
    
	DES_MakeSubKeys(bKey,subKeys);
    
    
	/* 取文件长度     */
    
	fseek(cipher,0,SEEK_END);    /* 将文件指针置尾 */
    
	fileLen = ftell(cipher);    /* 取文件指针当前位置 */
    
	rewind(cipher);                /* 将文件指针重指向文件头 */
    
	while(1){
        
		/* 密文的字节数一定是8的整数倍 */
        
		fread(cipherBlock,sizeof(char),8,cipher);
        
		DES_DecryptBlock(cipherBlock,subKeys,plainBlock);                       
        
		times += 8;
        
		if(times < fileLen){
            
			fwrite(plainBlock,sizeof(char),8,plain);
            
		}
        
		else{
            
			break;
            
		}
        
	}
    
	/* 判断末尾是否被填充 */
    
	if(plainBlock[7] < 8){
        
		for(count = 8 - plainBlock[7]; count < 7; count++){
            
			if(plainBlock[count] != '\0'){
                
				break;
                
			}
            
		}
        
	}   
    
	if(count == 7){/* 有填充 */
        
		fwrite(plainBlock,sizeof(char),8 - plainBlock[7],plain);
        
	}
    
	else{/* 无填充 */
        
		fwrite(plainBlock,sizeof(char),8,plain);
        
	}
    
    
	fclose(plain);
    
	fclose(cipher);
    
	return OK;
    
}

/*-----------------des 加密和解密函数----------------*/
//加密，将str字符串加密后写入文件 cipherFile，key是密钥
bool DesEncrypt(const char* content, char* key, const char* cipherFile);
//解密，将cipherFile的内容读取出来，解密后放入dest，dest内部会进行分配，但是外部要负责释放，key是密钥
void DesDecrypt(const char* cipherFile, char* key, char* & dest);


/*-----------------des 加密和解密函数----------------*/
//加密，将str字符串加密后写入文件 cipherFile，keyStr是密钥
bool DesEncrypt(const char* content, char* keyStr, const char* cipherFile)
{
	FILE* cipher = NULL;
	ElemType plainBlock[8], cipherBlock[8], keyBlock[8];
	ElemType bKey[64];
	ElemType subKeys[16][48];
    
    
	cipher = fopen(cipherFile, "wb");
	if (cipherFile == NULL)
	{
		return false;
	}
    
	memcpy(keyBlock, keyStr, 8);
	/*将密钥转换为二进制流*/
	Char8ToBit64(keyBlock, bKey);
	/* 生成子密钥 */
	DES_MakeSubKeys(bKey,subKeys);
    
	int nLength = strlen(content);
	int counter = nLength / 8;
	int remainder = nLength % 8; //余数
	int i = 0;
	while (counter != 0)
	{
		memcpy(plainBlock, content + 8*i, 8);
		DES_EncryptBlock(plainBlock, subKeys, cipherBlock);
		fwrite(cipherBlock, sizeof(char), 8, cipher );
		counter --;
		i ++;
	}
    
	if (remainder != 0) //不是8个字节的整数倍，那么要进行补全
	{
		memcpy(plainBlock, content + 8 * i, remainder);
		memset(plainBlock + remainder, '\0', 7 - remainder);
		plainBlock[7] = 8 - remainder;
		DES_EncryptBlock(plainBlock, subKeys, cipherBlock);
		fwrite(cipherBlock, sizeof(char), 8, cipher);
	}
    
	fclose(cipher);
	return true;
}

//解密，将cipherFile的内容读取出来，解密后放入dest，dest内部会进行分配，但是外部要负责释放，key是密钥
void DesDecrypt(const char* cipherFile, char* keyStr, char* & dest)
{
	FILE* cipher;
	int count,times = 0;
	long fileLen;
	ElemType plainBlock[8],cipherBlock[8],keyBlock[8];
	ElemType bKey[64];
	ElemType subKeys[16][48];
    
	if ((cipher = fopen(cipherFile, "rb")) == NULL)
	{
		return;
	}
    
	/* 设置密钥 */
    
	memcpy(keyBlock,keyStr,8);
    
	/* 将密钥转换为二进制流 */
    
	Char8ToBit64(keyBlock,bKey);
    
	/* 生成子密钥 */
    
	DES_MakeSubKeys(bKey,subKeys);
    
	fseek(cipher, 0, SEEK_END);
	fileLen = ftell(cipher);
	rewind(cipher);
    
	//为dest分配内存
	long destLength = (fileLen / 8 * 8) + (fileLen%8 == 0 ? 1 : 8);
	dest = new char[destLength];
	memset(dest,0, destLength);
	
	while(1)
	{
		fread(cipherBlock, sizeof(char), 8, cipher);
		DES_DecryptBlock(cipherBlock, subKeys, plainBlock);
		
		times += 8;
		if (times < fileLen)
		{
			memcpy(dest+times-8, plainBlock, 8);
		}
		else
		{
			break;
		}
	}
    
	/* 判断末尾是否被填充 */
    
	if(plainBlock[7] < 8){
        
		for(count = 8 - plainBlock[7]; count < 7; count++){
            
			if(plainBlock[count] != '\0'){
                
				break;
                
			}
            
		}
        
	}
    
	if(count == 7)/* 有填充 */
	{
		memcpy(dest+times-8, plainBlock, 8 - plainBlock[7]);
	}
    
	else/* 无填充 */
	{
		memcpy(dest+times-8, plainBlock, 8);
	}
	fclose(cipher);
}
/*
 int main()
 
 {   
 DES_Encrypt("1.txt","key.txt","2.txt");
 system("pause");
 DES_Decrypt("2.txt","key.txt","3.txt");
 getchar();
 return 0;
 }*/
